1. Field of the Invention
This invention relates to a primer, and more particularly a primer capable of imparting a good adhesion even to hardly adherable materials such as olefin plastics.
2. Description of the Prior Art
In general, polyolefin plastics such as polyethylene and polypropylene are materials to which adhesives can adhere with difficulty, and hence they are subjected to a surface modification treatment to improve adhesion, after which the adhesives are applied. Hitherto known methods for surface modification of, for example, polyethylene include chemical treatments using alkyl titanate, chromic acid, etc., and physical treatments in which the polyethylene is exposed to hot air, flame, ozone, ultraviolet light, corona discharge or the like, or applied with electron bonbardment.
The above treatments, however, require special chemicals or apparatus and thus have the disadvantages that their operation can not be made with simplicity. A simple method of enhancing the adhesion between materials includes a treatment with a primer, but no primer has been hitherto known which is effective for the polyolefin plastics.